Timer management services

Services for reading and spinning on the hardware timer. More...

Collaboration diagram for Timer management services:

Data Structures
struct	rt_timer_info
	Timer status descriptor. More...

Typedefs
typedef struct rt_timer_info	RT_TIMER_INFO
	Timer status descriptor. More...

Functions
static RTIME	rt_timer_read (void)
	Return the current system time. More...
SRTIME	rt_timer_ns2ticks (SRTIME ns)
	Convert nanoseconds to Alchemy clock ticks. More...
SRTIME	rt_timer_ticks2ns (SRTIME ticks)
	Convert Alchemy clock ticks to nanoseconds. More...
void	rt_timer_inquire (RT_TIMER_INFO *info)
	Inquire about the Alchemy clock. More...
void	rt_timer_spin (RTIME ns)
	Busy wait burning CPU cycles. More...

Detailed Description

Services for reading and spinning on the hardware timer.

Typedef Documentation

RT_TIMER_INFO

typedef struct rt_timer_info RT_TIMER_INFO

Timer status descriptor.

This structure reports information about the Alchemy clock, returned by a call to rt_timer_inquire().

Function Documentation

rt_timer_inquire()

void rt_timer_inquire

(

RT_TIMER_INFO *

info

)

Inquire about the Alchemy clock.

Return status information about the Alchemy clock.

Parameters

info	The address of a structure to fill with the clock information.

Tags

unrestricted

References rt_timer_info::period.

rt_timer_ns2ticks()

SRTIME rt_timer_ns2ticks

(

SRTIME

ns

)

Convert nanoseconds to Alchemy clock ticks.

Convert a count of nanoseconds to Alchemy clock ticks. This routine operates on signed nanosecond values. This is the converse call to rt_timer_ticks2ns().

Parameters

ns	The count of nanoseconds to convert.

Returns

The corresponding value expressed in clock ticks of the Alchemy clock. The resolution of the Alchemy clock can be set using the –alchemy-clock-resolution option when starting the application process (defaults to 1 nanosecond).

Tags

unrestricted

Examples:

cross-link.c, and rtcansend.c.

rt_timer_read()

RTIME rt_timer_read ( void  )

inlinestatic

Return the current system time.

Return the current time maintained by the Xenomai core clock.

Returns

The current time expressed in clock ticks (see note).

Tags

unrestricted

Note

The time value is a multiple of the Alchemy clock resolution (see –alchemy-clock-resolution option, defaults to 1 nanosecond).

Examples:

cross-link.c.

rt_timer_spin()

void rt_timer_spin

(

RTIME

ns

)

Busy wait burning CPU cycles.

Enter a busy waiting loop for a count of nanoseconds.

Since this service is always called with interrupts enabled, the caller might be preempted by other real-time activities, therefore the actual delay might be longer than specified.

Parameters

ns	The time to wait expressed in nanoseconds.

Tags

unrestricted

rt_timer_ticks2ns()

SRTIME rt_timer_ticks2ns

(

SRTIME

ns

)

Convert Alchemy clock ticks to nanoseconds.

Convert a count of Alchemy clock ticks to nanoseconds. This routine operates on signed nanosecond values. This is the converse call to rt_timer_ns2ticks().

Parameters

ns	The count of nanoseconds to convert.

Returns

The corresponding value expressed in nanoseconds. The resolution of the Alchemy clock can be set using the –alchemy-clock-resolution option when starting the application process (defaults to 1 nanosecond).

Tags

unrestricted